Rikon Grinder, CBN Wheel Types, Grit Choices

[tom lucas]

When I want to remove a lot of wood fast without regard for surface finish, I use a scraper with a burr raised on 80 grit. When I want to be more delicate with a scraper (not often unless it's a negative rake scraper), I'll grind on the 180 stone, then hone off the grinder burr and raise a new one with a carbide rod burnisher. That has been working for me. My thinking is that the roughly ground scraper cuts more like a deep gulletted blade where as the finely honed burr cuts more like a fine toothed blade. One cuts fast but leaves a rough surface and the other cuts slower but leaves a nicer surface. Neither burr lasts very long.

[Reed Gray]

I have heard all the sharpening discussions about coarser cuts better and lasts longer, and finer edge cuts better and lasts longer. While I have no electron microscope or meters to test how much pressure cutting takes, I must say, with the 'feel' I have developed over 20+ years of turning, that just doesn't hold up. Yes, I know the wood can make a big difference in how things cut, but I mostly turn Pacific Madrone which cuts like pear or green dogwood, and Oregon Myrtle/California Bay Laurel, and still 'feel' that the 180 edge lasts longer for roughing cuts, but it won't make as fine of a cut as the 600 grit gouges on some of the softer woods. For finish cuts, especially if the wood is prone to tear out, the 600 grit edge will cut more cleanly than the 180. I always use a fresh edge for finish cuts.

For scraper burrs, that was a curious comment about the grinder burr wearing off/folding over almost instantly. I use scrapers for all of my roughing on bowls. I haven't used M2HSS in some years, probably since Doug Thompson started making tools, and Dave Schweitzer at D Way also. The burr from a 180 grit wheel on those tools will last, easily for one good sized bowl. With the Big Ugly tool, which used tantung for the cutting material, I can turn several sets of bowls without needing to go back to the grinder. There is still a prominent burr left when I go back to the grinder. As to why the guy said his burrs folded over, I can only guess. You can oversharpen any tool. With a grinder, and a coarser wheel, you can get a very big burr, and it will be more prone to folding over. With a 180 grit wheel, I get a burr that is closer to being honed than one that is a raised edge of grinder duff. All you have to do to 'refresh' the cutting burr is hone it off, top side down, and then just lightly kiss the grinding wheel to the bevel.

I used to sharpen my scrapers on the 80 grit wheel, but out of curiosity, I started sharpening them on the 180 grit wheel. There was no noticeable difference in how they cut, so I started using the 180 grit wheel because it ate up less metal.

The only time I burnish burrs onto my scrapers is for shear scraping, and for NRSs. It does produce a longer lasting edge, and it seems to be sharper than the grinder burr. Some times for shear scraping I just go from grinder to wood, and when it gets dull, I burnish that burr down and then back up again. Maybe not as fine of an edge than I would get if I honed the burr down, but it works.

I do remember, some time ago, when the Tormek was still a new idea about how turners commented that the edge they got from it lasted far longer than the edge they got from the standard grinding wheels. Haven't heard that comment in a long long time. I was wondering if it would come up now that Tormek has a 1200 grit diamond wheel for their set up. I know John Lucas switched to them, but haven't heard anything else since then.

robo hippy

[John K Jordan]

... True you do get a nice fine edge from 600 grit wheels, however this is really only good for a finish cut and won’t hold that edge IMO. ...

My experience is different. I started with the fine Tormek sharpening and followed their recommendation to actually polish the edge. They provided credible logic why the polished edge would last longer. The problem with the Tormek is it takes a while to set up each time.

When I went to 350 grit CBN the honeed edge cut well but didn't seem to last as long. and I saw fine tool scratches on my spindles made from wood like ebony and cocobolo. Going to the polished 600 grit and then the 1200 grit the edges seem to last longer, with aggressive or finish cuts. And unsanded finish cuts on good wood could look like they were sanded to 600 or finer paper (depending on how steady my hands were!)

Looking at the sharpened and honed edges under a microscope show a big difference between grits. I don't use my clinical microscopes with high power for this but a 15/30x stereo microscope.

I also have a Sharp Check tester (https://www.edgeonup.com/eou_new_2016_004.htm) which puts a number on the sharpness of an edge. Lightly stropped edges on skews ground with 600 and 1200 tested far sharper than those on coarser wheels. (Not as easy to test on gouges with curved tips)

But again, MUCH depends on the type of turning and the grind on the tool. I think turning delicate spindles from dense, fine grained wood different from hogging out green wood bowls or finish cuts on dry bowls and platter that will be power sanded.

JKJ

[John K Jordan]

...I mostly turn Pacific Madrone which cuts like pear or green dogwood, ...

As, a Madrone expert! A few years Graeme Priddle gave me a supply of kiln dried Pacific Madrone which I had never turned. It is beautiful! Again, I mostly turn small things and always turn dry. I rate dry madrone as of the soft side but with an incredibly fine grain that takes detail and leaves a very smooth surface without sanding, but sands SO smooth. Great for burning and carving. I have my stash guarded by a mean dog and an attack turkey. Wish I could get a truckload!

A few years ago I also got a bunch of highly figured boiled Madrone 3x3 turning stock from Big Monk. I'm still letting it dry but it's about ready to turn. Can't wait to give that a try!
It is coated with paraffin wax which I think causes the redish color. The figure is almost like birds eye or quilted in places. Is that common in Madrone?

madrone_figured.jpg

JKJ

[Allen Mattsen]

I think I'm gonna go with the 1hp grinder and 2 mega-square wheels at 180/600 grit.

Two things: any reason not to get the grinder from Ken - is there any need for the other removed components and white wheels it comes with that are removed? And, any reason to get a different profile wheel than the mega squares? So far it seems nobody has made a good case for anything else. Thanks 👍🏼.

PS since I live in Vancouver, WA / Portland area maybe I can get some Madrone eventually - or chop down the small, burly apple tree in my neighbor's front yard 😅

[David Walser]

Allen -- The ONLY reason I didn't buy my grinder from Ken is that I could get it cheaper after shipping from CSUSA. I cannot remember how much I saved, but it was more than $25. And, I have a use for the A/O wheels that Rikon ships the grinder with. I have another, 1/2 hp grinder, that I intend to use for softer materials. Those wheels will work well on that grinder.

[William C Rogers]

John, no doubt that a finish cut from a gouge sharpened on a 600 grit will be better. However IMO not that much. I don’t have a 600 wheel, but do have a leather belt ob a grinder I have used to polish a sharpened gouge. The better the finish on the gouge the better the cut finish. I don’t do that because the advantage is not enough to warrant it. Most of what we do are roughing cuts. For roughing cuts, I feel tools from a 180 grit are just as good as a tool with a polished bevel. A new turner is not going to know how to even make a finished cut or how to sharpen his tools, 80 grit sandpaper is his/her best friend. The OP has decided on the 180 -600 combination, but I still feel the 180 -80 combination will be far more useful to a new turner. I still have no desire to get a grit higher than 180. I think my older 180 is now more like 350 due to wear.

Edit: I will add since I mainly use Thompson and D-Way tools I find it not as necessary to get that super edge with those tool steels.

[Brian Tymchak]

The
This is part of my sharpening setup.
I also have two other bench grinders and a second Tormek not shown here.
Attachment 451029
I use conventional aluminum oxide wheels for mild steel.

JKJ

John, what are you sharpening on your Tormeks? I've got a Jet slow speed grinder that I don't use and have been thinking about selling but I wonder if I'd be missing an opportunity if I did.

Thanks!

[Reed Gray]

As for Pacific Madrone, it always has a red tint. Some times I have had some with purple in it. The smaller trees tend to be very pale, but the finish brings out some pink. As for drying it, there is a risk of the outside looking very nice, but when you cut into it, the inside can be shattered. I got a 20 years dry burl that was solid on the outside, and shattered on the inside. I would suggest you turn it ASAP. Because of a very high water content, I think only Sycamore approaches it, it generally warps way past the 10% rule. You can stabilize it by boiling. It is fairly hard when dry, but has low 'crush' strength, which means it kind of dents easily and doesn't make good hammer handles. I would think that if glued together, you could get some nice rolling pins out of it. It does cut very smooth and clean, and a NRS works great for cleaning it up, and of course the NRS must have a fresh edge. Smooth even grain, and is great for carving. I have a friend who is a spoon carver and had never tried it. It is now his favorite wood. Not sure about the birds eye pattern, though I have seen some nicely figured pieces.

As for the grinders from Ken, I believe he sells them without the blade guards. I consider them essential for metal dust control.

robo hippy

[David Walser]

Brian -- I cannot speak for John. However, I also have a Tormek and have recently added a CBN wheel to it. I have my bench grinder set up for use with Tormek's jigs. When shaping a tool, I start with the grinder and finish with the Tormek. If all I need do is touch up an edge, I just use the Tormek. The great thing about using the Tormek jigs with my bench grinder is the tool doesn't come out of the jig when moving from grinder to Tormek. This eliminates any potential registration issues with how the tool is held in the jig.

The only exception to this is my scrapers. I don't feel the need to polish the bevel of my scrapers to the same extent I polish the bevels of my other turning tools. For scrapers, I hone off the bur raised at the grinder and then raise a new bur with a burnisher. (To hone of the bur, I use the leather wheel of Tormek, no jig necessary.) With some woods and when cutting end grain, I find I get better results with no bur on my scrapers. That may vary from one blank to the next. So, I experiment. If the bur isn't producing good results, I hone it off and try cutting without the bur. I also use negative rake scrapers on resins, again, without the bur.

[John K Jordan]

John, what are you sharpening on your Tormeks? I've got a Jet slow speed grinder that I don't use and have been thinking about selling but I wonder if I'd be missing an opportunity if I did.

Thanks!

I use the Tormek in that picture with a 1200 grit CBN primarily to sharpen my spindle gouges and occasionally for a skew, although I generally sharpen the skews on the 600 grit 8" CBN wheel on a bench grinder. (I like the slightly more concave bevel shape from the smaller diameter wheels for the skews)

I like the edge the 1200 grit gives me on the spindle gouges.I haven't tried a 1200 grit wheel on the bench grinder, maybe I'd like it. I also use the Tormek when occasionally reworking a damaged carving chisel - with the slow speed it's harder to make a mistake and mess up something.
I also like the leather honing/stropping wheel on the Tormek. I use it on almost every tool I sharpen except for scrapers. I operate the Tormek on a foot switch for quick honing.

I have a 600 grit CBN on the second Tormek and currently have it loaned to a student.

If you are happy with the 8" wheels, yes, sell the slow speed! There are some who like the Tormek style grinders to sharpen knives and hand tool.

JKJ

[David M Peters]

Allen, getting the grinder & wheels directly from Ken is a good choice. I have almost the same setup (1HP/Mega Squares/80/300) and it arrived pre-assembled and tuned up. The wheels run with little to no runout, none that I've ever cared to try measuring.

[Allen Mattsen]

Update: I went ahead and ordered the 1HP Rikon grinder and 180/600 mega square wheels from Ken. Big bullet to bite, but I feel good about the decision being a well informed one thanks to you fine folks. Also, hopefully this purchase ends up the long term solution I expect it will. I won't feel I need to upgrade the grinder, and should be happy with the wheels. Kinda wish I had an 80grit for fast material removal on new or reconditioning tools (such as my chipped Japanese chisel) but I'll make do. Trying my best to set up for the long haul and this is a good start toward sharp tools. 😎👍🏼

[tom lucas]

good choice.

[Brian Tymchak]

Brian -- I cannot speak for John. However, I also have a Tormek and have recently added a CBN wheel to it. I have my bench grinder set up for use with Tormek's jigs. When shaping a tool, I start with the grinder and finish with the Tormek. If all I need do is touch up an edge, I just use the Tormek. The great thing about using the Tormek jigs with my bench grinder is the tool doesn't come out of the jig when moving from grinder to Tormek. This eliminates any potential registration issues with how the tool is held in the jig.

The only exception to this is my scrapers. I don't feel the need to polish the bevel of my scrapers to the same extent I polish the bevels of my other turning tools. For scrapers, I hone off the bur raised at the grinder and then raise a new bur with a burnisher. (To hone of the bur, I use the leather wheel of Tormek, no jig necessary.) With some woods and when cutting end grain, I find I get better results with no bur on my scrapers. That may vary from one blank to the next. So, I experiment. If the bur isn't producing good results, I hone it off and try cutting without the bur. I also use negative rake scrapers on resins, again, without the bur.

I use the Tormek in that picture with a 1200 grit CBN primarily to sharpen my spindle gouges and occasionally for a skew, although I generally sharpen the skews on the 600 grit 8" CBN wheel on a bench grinder. (I like the slightly more concave bevel shape from the smaller diameter wheels for the skews)

I like the edge the 1200 grit gives me on the spindle gouges.I haven't tried a 1200 grit wheel on the bench grinder, maybe I'd like it. I also use the Tormek when occasionally reworking a damaged carving chisel - with the slow speed it's harder to make a mistake and mess up something.
I also like the leather honing/stropping wheel on the Tormek. I use it on almost every tool I sharpen except for scrapers. I operate the Tormek on a foot switch for quick honing.

I have a 600 grit CBN on the second Tormek and currently have it loaned to a student.

If you are happy with the 8" wheels, yes, sell the slow speed! There are some who like the Tormek style grinders to sharpen knives and hand tool.

JKJ

David, John, thanks for your replies. Appreciate the details. Think I'll hold on to the Jet wet sharpener until I fully define my sharpening needs. David, I never considered using the Tormek jigs (I have all the Jet jigs) on a bench grinder. Thanks for that idea. I had considered the wet sharpener too slow for my nature. Maybe I just need to slow down a bit..

Thanks!